Short answer

There is no standard cannabis dose for PTSD. No cannabis product holds FDA approval for PTSD. Neither the VA nor the NIH publishes a dosing schedule. Published trials and clinic reports span a wide range, from 1 mg to 2.5 mg of THC per dose for new users up to hundreds of milligrams per day in heavy users. That spread shows the absence of a target dose, not a menu of options.

cbd for ptsd vs thc

What the evidence shows

Reviews of cannabis for PTSD report mixed results. Some users report less insomnia and fewer nightmares. Controlled trials have not confirmed symptom relief that beats placebo. Observational studies link heavy use to worse PTSD scores over time, not better ones.

cannabis for ptsd treatment research

First-line PTSD care does not involve cannabis. VA and other guidelines list trauma-focused therapy (CPT, PE, EMDR) and the FDA-approved drugs sertraline and paroxetine. Cannabis appears in none of those protocols.

cbd for ptsd vs thc

Administration routes and timing

Inhaled

Onset is 1 to 10 minutes. Peak effect arrives in about 30 minutes. Effects last 2 to 4 hours. Absorption varies with inhalation depth and breath hold.

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Oral

Onset is 30 to 120 minutes. Peak effect arrives at 2 to 4 hours. Effects last 6 to 8 hours. Absorption varies by food, formulation, and liver metabolism. Edibles cause more overdose-type reactions because users re-dose before the first dose takes effect.

Oromucosal and sublingual

Onset is 15 to 45 minutes. Peak effect arrives at 1 to 2 hours. Fewer of these products are sold in the US.

Topical

Topicals produce no psychoactive effect and no systemic THC levels of note. No evidence supports them for PTSD symptoms.

Ratios and potency

Flower in the US tested at about 15% THC in 2021, up from about 4% in 1995. Two puffs of 15% flower in 2021 deliver more THC than 10 puffs of 1995 flower. Count milligrams when a label exists.

Trials of CBD for PTSD used oral doses from 25 mg to 300 mg per day. THC-dominant and balanced 1:1 products appear in surveys. No trial has compared ratios head to head for PTSD.

Starting points reported in research and clinics

  • Inhaled: 1 to 2 puffs of low-potency flower, then wait 15 minutes.
  • Oral THC: 1 to 2.5 mg per dose, once per day, in the evening.
  • Hold the same dose for 3 to 7 days before any increase.
  • Keep a written log of dose, route, time, and symptom scores.

These are harm-reduction conventions. They are not validated protocols.

What to track

  • PCL-5 score every 2 to 4 weeks.
  • Nightmare count per week.
  • Hours of sleep.
  • Grams or milligrams used per day.
  • CUDIT-R score for cannabis use disorder.
  • PHQ-9 score for depression.

Risks

  • About 3 in 10 cannabis users develop cannabis use disorder.
  • Withdrawal includes irritability, insomnia, and appetite loss.
  • High-THC products raise psychosis risk, more so with a family history.
  • Cannabinoid hyperemesis syndrome causes repeat vomiting.
  • CBD inhibits CYP2C19 and CYP3A4. It raises levels of clozapine, warfarin, and tacrolimus.
  • Smoked cannabis irritates airways.

Stop rules

  • PCL-5 score does not drop after 8 weeks of steady use.
  • Use climbs to cope with distress.
  • Panic, paranoia, or vomiting after use.
  • Any dose increase in the same week as a crisis.

Unknowns

No data establish a dose-response curve for PTSD. No data show that cannabis improves trauma-focused therapy outcomes. No trial has followed PTSD patients on cannabis past 12 months. State law varies. Federal law lists cannabis as Schedule I.